Actuator with deformable bump stops, fluid buffing and pressure bleed means



July 16. 1968 G. SPERL ETA 3,392,635

ACTUATOR WITH DEF MABLE BUMP ST FLUID BUFF'ING AND SSURE BLEED MEANS Filed Dec. 30, 1965 4 Sheets-$heet 1 INVENTORS Gar/2 /6 Spam m' M! y W ATTORNEYS July 16. 1968 s ER ET AL 3,392,635

ACTUATOR WITH DEFORMABLE BUMP STOPS, FLUID BUFFING AND PRESSURE BLEED MEANS Filed Dec. 50, 1965 4 Sheets-Sheet 2 I N VEN TOFLS 60772165 $P2L AUL 5. /55

BY ARK/M $1 v-% I ATTORNEYS July 16. 1968 cs. SPERL ET AL 3,392,635 ACTUATOR WITH DEFORMABLE BUMP STOPS, FLUID BUFFING AND PRESSURE BLEED MEANS Filed Dec. 50, 1965 4 Sheets-Sheet 5 mm W INVENTORS @0772 use 5P524 /?4 u z 5. 6/55 m MM ATTORNEYS July 16. 1968 e. SPERL ET AL 3,392,635

ACTUATOR WITH DEFORMABLE BUMP STOPS, FLUID BUFFING AND PRESSURE BLEED MEANS Filed Dec. 50, 1965 4 Sheets-Sheet 4L is M 49 57 INVENTOR5 Germ/5 mm; R404 5' 6/55 55 BY MM VM ATTORNEYS United States Patent ACTUATOR WITH DEFORMABLE BUMP STOPS, FLUID BUFFING AND PRESSURE BLEED MEANS Gottlieb Sperl, Williamsville, and Paul E. Gies, Eggertsville, N.Y., assignors to Houdaille Industries, Inc.,

Buffalo, N.Y., a corporation of Michigan Filed Dec. 30, 1965, Ser. No. 517,734 16 Claims. (CI. 9285) ABSTRACT OF THE DISCLOSURE A heavy duty rotary hydraulic actuator has a housing defining a working chamber which is subdivided into a plurality of subchambers by a plurality of abutments on the housing and vanes of a wingshaft. Malleable metal projections on the bump stop faces of the vanes are deformable on striking the stop faces of the abutments to equalize bump-out contact. Hydraulic ports adjacent to the abutments are closed off by the vanes for fluid buffing and pressure relief passage orifices across the ends of the vanes prevent hydraulic lockout.

This invention relates to improvements in heavy duty type actuators adapted for use in hydropneumatic suspension systems for the bogies of endless track running gear for tractors, battle tanks, and the like.

Heretofore, extreme excursions of the road arms carrying the bogie wheels have been arrested by a lug on the road arm making contact with stop ears on the actuator mounting flange. Failures have been experienced due to breaking of either the road arm stop lugs or the actuator housing stop ears.

An important object of the present invention is to provide a new and improved means for arresting extreme excursions of the road arm by means located internally of the associated rotary actuators.

Another object of the invention is to provide a new and improved actuator structure especially suitable for use with the road arms of bogies in which bumpout takes place internally and simultaneously on all of a plurality of vanes of the wing shaft of the actuator.

A further object of the invention is to provide new and improved means for equalizing bumpout contact between the vanes of a rotary hydraulic actuator wing shaft and the abutments.

Still another object of the invention is to provide a new and improved hydraulic actuator having improved hydraulic damping means in association with internal bump stops.

A still further object of the invention is to provide a new and improved internal construction in a rotary actuator for effecting hydraulic damping without creating a hydraulic lock or causing exceedingly high internal pressures and enabling return rotation without the need for check valves.

Yet a further object of the invention is to provide a new and improved hydraulic actuator construction embodying a simplified and more reliable hydraulic checking system.

Other objects, features and advantages will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is an end elevational view of an actuator embodying features of the invention.

FIGURE 2 is an enlarged fragmentary sectional detail view taken substantially on the line II-II of FIGURE 1.

FIGURE 3 is a fragmentary schematic illustration of a hydropneumatic suspension system in which actuators 3,392,635 Patented July 16, 1968 according to the present invention are especially adapted to be used.

FIGURE 4 is a side elevational view of the wing shaft of the actuator.

FIGURE 5 is an end view of the same wing shaft.

FIGURE 6 is a substantially enlarged fragmentary elevational detail view of the encircled portion VI of FIGURE 5;

FIGURE 7 is an inner face elevational view of the rear, ported end cover of the actuator; and

FIGURE 8 is a slightly enlarged fragmentary sectional detail view taken substantially on the line VIII-VIII of FIGURE 7 and showing the end cover in its mounted relationship.

On reference to FIGURES 1, 2 and 3, the invention is exemplified in a bogie actuator 10 comprising a tubular housing body 11 provided on its front end with a radially outwardly extending attachment flange 12 provided with symmetrically peripherally spaced bolt holes 13 therethrough and by which the actuator is fixedly secured to the carriage in proper relation to an endless crawler track suspension system to support rotatably a bogie arm shaft 14. On the outer or front half of the shaft 14 is mounted a radially extending bogie or road arm 15 carrying on its outer end portion a suitable stub axle mounting a bogie wheel 17 which, together with the generally several companion bogies supports an endless track tread 18 of the vehicle.

A prime function of the actuators 10 in the suspension system is, of course, to maintain substantially equalized traction thrust of the bogies on the endless tread 18. To this end, the hydropneumatic system includes means connecting the actuator 10 to a hydraulic pressure fluid supply, and including a pressure fluid line 19 leading t0 a high pressure accumulator 20 and a low pressure accumulator 21 and communicating through an orifice check valve damper unit 22 equally with each of the actuators 10 by way of pressure line 22a. A drain line 23 leads from the front Wheel actuator 10, and an interconnecting line 24 connects the companion actuators 10 for pressure equalization and for seal drainage.

Each of the actuators 10 is of the rotary vane type in which the elongated tubular housing 11 has therein a generally cylindrical working chamber 25 equally subdivided by a plurality, herein three, fixed abutments 27 (FIG. 1) which are desirably integral in one piece with the housing member 11. Slidably cooperative with the inner ends of the abutments 27 is a cylindrical, tubular wing shaft 28 having integral with its outer perimeter vanes 29 complementary to the abutments 27 and slidably engaging the cylindrical surface defining the chamber 25 within the subchambers into which it is subdivided by the abutments 27. Each of the vanes 29 has a longitudinally extending radial slot within which is mounted a vane seal 30 having a spacer disc 31 about which it is mounted as best seen in FIGURE 2. Similar sealing assembly structure is provided for each of the abutments 27.

Closure means at the front end of the working chamber 25 comprise a front end closure disc 33 telescoped into and secured to the body member 11 as by means of screws 34. Rotary support for a front end journal portion 35 of the wing shaft is provided by the end closure 33 through a bearing assembly 37. A shaft seal 38 mounted in the inner corner of the end closure 33 engages the shaft journal 35 at the outer end shoulder of the wing shaft, and a hub seal assembly 39 mounted in the inner face of the enclosure member 33 engages the wing shaft hub contiguous to the vane ro-ot diameter of the wing shaft, with a seal drain passage 40 leading from the base of the seal groove.

At its opposite or rear end, the actuator housing comprises an end closure disc 41 which is telescopically assembled with the rear end portion of the main housing member 11 in closing relation to the working chamber 25 and secured in place as by means of screws 42. Rotary support for a rear journal 43 on the wing shaft 28 is provided by bearing assembly 44 carried by the annular closure disc 41.

Corotational attachment of the associated bogie shaft 14 within the tubular wing shaft 28 is effected by means of an annular intermediate internal spline area 45 on the wing shaft bore.

Connection of the actuator 10 with the hydraulic system is effected through a manifold 46 (FIG. 2) secured to the outer end of the rear end closure member 41. Hydraulic communication between the working chamber 25 and the manifold 46 is effected herein at one respective side of each of the abutments 27 by means of a port 47 through the end member 41 leading from an annular distribution groove 48 in the back face of the end member (FIGS. 1, 2, 7 and 8). Opening through the inner face of the end member 41 at the respective opposite sides of the abutments 27 are communication ports 49 leading from an annular distribution groove 50 in the outer face of the end member spaced from the groove 48 and also communicating with the manifold. Through this arrangement, as the respective vanes 29 approach the respective abutments 27 between which they are located, the end faces of the vanes opposing the end cover member 41 move closingly across the respective ports 47 or 49, as the case may be, with a throttling, wing shaft rotation retarding action to buffer impact of the sides of the vanes against the opposed sides of the abutments.

According to the present invention, means are provided for equalizing impact or bumpout of the vanes 29 against the respective opposed abutments 27, and also to avoid buildup of excessive internal pressures during the throttling coaction of the vanes 29 with the ports 47 and 49.

Theoretically, it should be possible to have the abutments and the vanes of the actuator so accurately relatively and complementally machined as to afford simultaneous bumpout of the faces of all of the vane-s with the opposed abutments. Practically, however, this is too diflicult and costly. As a practical solution of the problem, we provide one of the opposed bumpout surfaces between each of the abutments 27 and vanes 29 with means which will automatically adjust in operation and compensate for any minor inaccuracies, manufacturing tolerance variations, and the like, which might otherwise tend to unbalance the load during impact between the vanes and abutments during extreme excursions of the associated bogie assembly. Conveniently such means are provided on the respective opposite sides of each of the wing shaft vanes 29 and comprise an abutment land or bump stop 51 and of substantial impact face area provided with shallow malleably deformably yieldable metallic element projection means 52 thereon. (FIGS. 1, 4, and 6). Each of the bump stops 51 has its face complemental to the opposing face of the adjacent abutment 27 In a desirable form the deformable means 52 are in the form of shall-ow, narrow ribs, with two such ribs extending longitudinally from end to end of the bump stop face and in closely spaced relation along the central portion of the width of the bump stop. As best seen in FIG. 6, each of the integral deformable ribs 52 has a preferably fiat crown 53 and sloping opposite side walls 54. In a typical construction where the working chamber diameter is about eight inches, and the width of the bump stop face is about .625 inch, the compensating ribs 52 have been about .020 to .025 inch in height, with a crown width of about .030 inch, a root or base width of about .065 inch and spaced apart about .06 inch.

By the proportioning and arrangement of the compensating ribs 52, metal-to-metal contact between the vanes and the abutments is automatically balanced and synchronized by the ability of those of the compensating ribs 52 which make initial contact with the opposing abutment faces to yield and How under the compression until all of the compensating ribs or the associated bump stop faces make simultaneous and load-balanced contact with the respective opposed abutment faces. As a result of the equalization in impact or bumpout load thus attained on the abutments and vanes, uneven stresses are avoided and likelihood of failure at least greatly reduced.

As the wingshaft vanes 29 approach stopping contact with the abutments 27, and the ports 47 or 49, as the case may be, are progressively closed by the vanes to restrict fiow therethrough and produce hydraulic damping or buffing, it is desirable to attain maximum buffing values but to avoid excessively high internal pressures and/or a hydraulic lock condition. Heretofore, this has commonly been accomplished by a system of relief and check valves. Herein, this desirable result is attained by valveless buifer means comprising bypass orifices afforded by restricted internal pressure bleed across those ends of the vanes 29 which oppose the housing end member 41. To this end, the end member 41 has in the inner end of its shaft bore a shaft seal 55 separated by an annular spacer ring land 57 from a hub seal assembly 58 having at least one drain port 59 leading therefrom and opening through an annular inner face area 60 of the end member 41 on substantially the radial center line of one of the abutments 27. This area 60 is slightly spaced from the adjacent ends of the vanes 29, as indicated in FIG. 2, while the relatively offset surface of the spacer land 57 makes sliding contact with the opposing wing shaft hub shoulder. In a construction of the general internal dimensions previously indicated, a typical differential of about .002 to .004 inch in the recessed relation of the end face surface 60 relative to the land surface 57 has been found suflicient for the purpose. Without diminishing satisfactory operational pressures in the actuator, the narrow bleed orifice relationship across the ends of the vanes 29 afforded by the inset relationship, and thus maintained clearance, of the slightly inset end face surface 60, sufficiently relieves terminal pressure to avoid excessive and possibly damaging pressure buildup as the bump stops approach bumpout contact with the abutments. Furthermore, after bumpout, the controlled clearance between the ends of the vanes 29 and the surface 60 prevents hydraulic lockout by providing a means for return flow from the generally closed off ports 47 or 49 to drive the wingshaft in the reverse direction. During reversal, the pressure fluid enters between the abutments and the respective sides of the vanes as permitted by the spacing afforded by the bump stops.

It will be understood that minor modifications of the features disclosed herein may be accomplished by those versed in the art, and we desire to claim as our invention all such modifications as properly come within the scope and spirit of the embodiments described herein.

We claim as our invention:

1. A rotary vane fluid operated actuator of the character described including an enclosing housing defining a cylindrical working chamber having a plurality of equally spaced abutments provided with stop faces and a wing shaft rotatably mounted in said housing with an equal plurality of vanes in said chamber and presenting stop faces for bump stopping engagement with said abutment faces, and comprising:

malleably yieldable bumpout projections integral with certain of said vanes and abutments for synchronizing stop impact of the stop faces; and

fluid buffer means cooperatively related to said vanes for damping said stop impact and including means for preventing excessive internal buffer pressures.

2. An actuator as defined in claim 1, in which said bumpout projections comprise deformable elements integrally on said stop faces of the vanes.

3. A actuator as defined in claim 1, in which said means for preventing excessive pressure comprise bleed orifice bypass passages defined between said housing and certain ends of' said vanes at least adjacent said abutments..

V 4. A rotaryfvane hydraulic actuator comprising:

.Qa tubular: housing body defining a cylindrical working 'chamberan'd having a plurality of integral equally spaced abutments projecting'into said'cha'rnber and having opposite stop faces, 7

a wing shaft having oppositely extending journal portions and an intermediate hubportion provided with radially extending integral vanes equal in number to said abutments and equally spaced and operatively projecting into said chamber between said abutments and having bump stop faces thereon opposingly relatedto said abutment faces, 7

deformable bumpoutiprojections on said bumpout faces of the vanes for automatically equalizing engagement and thereby synchronizing stop impact of the faces of the vanes against the faces-of the abutments,

' respective opposite end closures journalling said-journal portions of the wing shaft and secured to the respectiveopposite ends of said body in closing relation to said working chamberwith inner faces of the closure member s closely opposing the ends of said vanes and abutments,

one of said cover members having hydraulic pressure ports therethrough communicating with said working chamber adjacent to said abutments and located to be closed by the vane ends to develop buffing pressure to damp impact of the vanes and abutments durin extreme rotary excursions of the wing shaft, and excessive-pressure-relieving orifice means at least adjacent to said abutments and defined between the inner face of said ported cover member and the op posed ends of said vanes.

5. An actuator as defined in claim 4, in which said orifice means comprise a slight spaced relation between said inner face and said opposed vane ends, and a spacer surface on said inner face engages an opposing surface of said vane shaft hub to maintain said orifice spacing.

6. For use in a hydropneumatic suspension system for an endless track running gear including a bogie having a road arm with a control shaft:

a rotary actuator vane shaft adapted to be corotatively coupled with said control shaft,

said vane shaft having a hub provided with a plurality of equally spaced radially outwardly extending metallic vanes each of which has at least one bump stop face including integral metallic automatic impact synchronizing malleably deformable adjustment projection means thereon,

an actuator housing enclosing said vane shaft and defining a work chamber about said hub and vanes with integral abutments equal in number and spacing to said vanes and extending into working engagement with the wing shaft hub between the vanes and affording stop faces opposing said bump stop faces, and

means for connecting the actuator working chamber in a hydraulic pressure system.

7. For use in a hydropneumatic suspension system for an endless track running gear including a bogie having a road arm with a control shaft:

a rotary actuator vane shaft adapted to be corotatively coupled with said control shaft and having a hub provided with a plurality of substantially equally spaced radially outwardly extending vanes,

a housing having means thereon for fixed attachment of the housing to a vehicle carriage and defining a working chamber having substantially equally spaced abutments in equal number to said vanes and within which chamber said hub is operatively located with said vanes interposed between said abutments,

means for connecting said working chamber with a hydraulic pressure system and including ports disposed adjacent to said abutments'to be respectively substantially closed off by said vanes, and

v a portion of said housingwithin said chamber opposing said vanes defining atleast adjacent to said abutments valveless pressure relief bypass clearance 'orifice passage means with said vanes to preclude hydraulic lock and to prevent excessive internal pressures in the rotary operations of the wing shaft i the housing when the ports are substantially closed 7 off by the vanes.

A rotary actuator especially adapted for use in a hydropneumatic bogie suspension system and comprising:

a tubular wing shaft having means for coupling corotatively therein of a bogie shaft,

' opposite journal portions and an intermediate hub por tion on said wing shaft,

" said hub portion having a'plurality of radially extending equally spaced vanes each of which has'at least one bump stop face,

a housing having means for fixedly securing to a vehicle frame and definingtherein a working chamber having a plurality of abutments equal in number and spacing to said vanes and with which'the vanes are interposed in working relationship and presenting stop faces opposing said bump stop faces, and substantially rigid bumpout equalizing malleably deformable metallic projections integral with said vanes and adapted to yield under compression against said stop faces of the abutments for synchronizing bumpout and equalizing torque loads between the vanes and abutments.

9. An actuator as defined in claim 8, in which said projections comprise a plurality of said integral deformable metallic projections on each of said bump stop faces.

10. In combination in an actuator of the character described:

a housing defining a working chamber having a plurality of substantially equally spaced abutments therein dividing the chamber into compartments,

a wing shaft rotatively mounted in the housing and having an equal number of equally spaced vanes extending into said compartments between said abutments,

said vanes having bumpout faces opposing complementary stop faces of the abutments,

each of said vanes having a shallow integral metallic substantially rigid malleably deformable bumpout equalizing rib projection compressibly engageable during bumpout with its opposing abutment stop face and automatically yieldable to effect bumpout synchronization and balancing of torque load forces on the abutments and vanes.

11. An actuator as defined in claim 10, in which said ribs extend longitudinally throughout the length of each of the associated bumpout faces.

12. In a rotary vane actuator of the character described including a housing having abutments therein and a Wing shaft having metallic vanes cooperative with the abutments, the improvement comprising:

a plurality of closely spaced shallow malleably deformable metallic bumpout equalizing ribs integral with the vanes and which oppose the abutments for automatically yielding in operation to synchronize bumpout and thus balance torque loads on the vanes and abutments.

13. In a rotary actuator construction of the character described,

a wing shaft having a hub provided with a plurality of radially extending substantially equally spaced metallic vanes each of which has at least one bumpout face adapted to engagingly oppose a stop face of a corresponding abutment,

and metallic malleably deformable bumpout equalizing projections integral with said vanes.

14. A construction as defined in claim 13 in which said projections comprise a pair of closely spaced longitudinally extending shallow ribs on each of said bumpout faces.

15. A construction as defined in claim 14 in which said ribs have substantially fiat crowns and sloping sides.

16. In a rotary hydraulic actuator construction of the character described,

a tubular housing body defining a working chamber and having abutments projecting radially inwardly into the chamber,

a wing shaft rotatively mounted in said body and having a hub opposingly engaging the tips of said abutments and carrying vanes interposed between said abutments and slidably engaging said body in said chamber and subdividing the chamber into a plurality of subchambers,

end closures on said body closing the respective opposite ends of the chamber and opposing the adjacent ends of the abutments and vanes,

means for connecting said subchambers with a hydraulic pressure system and including ports disposed adjacent to said abutments to be respectively substantially closed off by said vanes,

a shoulder on said hub opposing one of said end c10- sures,

8 I a spacer surface on said one enclosure slidably engaging said shoulder, and an inset surface area on said one closure member defining with the opposing ends of the vanes a pressure relief orifice passage across said ends and communicating with said subchambers.

References Cited UNITED STATES PATENTS 1,250,569 12/1917 Desmond 92-120 2,339,042 I/ 1944 Anderson 92-122 2,778,338 1/1957 Shafer 92-122 2,806,451 9/1957 Vinkler et al. 92-122 X 3,136,228 6/1964 Dailey 92-85 3,155,013 11/1964 Rumsey 92-120 X 3,195,421 7/1965 Rumsey et a1. 92-122 3,255,675 6/1966 Reeve et a1 92-85 X 3,262,522 7/1966 Johnson et al 280-4323 3,303,756 2/1967 Geeson 92-85 MARTIN P. SCHWADRON, Primary Examiner.

I. C. COHEN, Assistant Examiner. 

